Fluid speed-regulator for elevators



(No Model.)

W. E. NIGKERSON. FLUID SPEED REGULATOR FOR ELEVATORS.

No. 403,436. Patented May 14, 1889..

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XVILLIAM E. NIOKERSON, OF CAMBRIDGE, MASSACHUSETTS.

FLUID SPEED-REGULATOR FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 403,436, dated May 14, 1889.

Application filed February 5, 1889. Serial No. 298,559. (No model.)

To all whom it may concern:

Be it known that 1, WILLIAM EMERY NICK- ERSON, of Cambridge, in the county of Mid dlesex and State of Massachusetts, have invented certain new and useful Improvements in Fluid Speed-Regulators for Elevators, of which the following, taken in connect-ion with the accompanying drawings, is a specification.

My invention consists in combining with the carriage of an elevator a retarding-rope, the velocity of motion of which is governed by the descent of a piston, said piston working in a cylinder full of fluid, which may be open at the top, as it requires no stuffing-box or appliance to prevent leakage, and governed in its velocity by fluid-passages and auto matic valves.

My invention is embodied in the mechanism shown in the accompanying drawings, in which Figure 1 is an elevation showing such parts as are required to illustrate the application of my device to an elevator. Fig. 2 is a vertical section taken through the retardingcylinder, also showing the parts directly connected with the cylinder.

In Fig. 1, C represents the elevatorcarriage, and K the hoisting-rope, which passes over the pulley K and down to the hoistingengine.

R, Fig. 1, is a rope for retarding or regulating the velocity of descent of the elevatorcarriage. This rope passes over the fixed pulley R, down under the fixed pulley R and over the moving pulley R attached to the head of the piston-rod P, thence to the fastening R at the head of the cylinder D.

The cylinder D has at its base B a fixed pulley, R and at its upper end wing-pieces H II, which serve to hold and support two posts, H H, which are united at the tops by the cross-piece H to which they are firmly connected. The posts H H serve as guides for the piston cross-head P". Said piston cross-head also serves as a support for the housing P P, Fig. 2, for the pulley R D is a piston attached to the lower end of the rod P. (See Fig. 2.) The piston D has openings (1 d, which are closed by the sliding The sliding valve D may be made so much smaller than the cylinder as to allow a free passage of fluid between it and the cylinder; or it may have openings, as shown at e c, Fig. 2.

The valve in its normal position does not affect the passage of fluid through the openings d (Z in the piston D, and only acts when the velocity of descent of the elevator-carriage is so great as to force the piston downward so rapidly as to create an upward flow through the piston of sufficient force to cause the valve D to slide up against the piston and close the openings (1 d. This action will check the descent of the piston to the desired extent. The descent of the piston can be still further regulated by the valve V in the pipe D, which communicates between the lower end of the cylinder and the upper part, as shown in Fig. 2. The piston P is drawn up by the retracting-weight P, attached to the rope P which passes over the pulley P. This Weight also may serve partially or wholly the purpose of the ordinary counterbalanceweight usually used in elevators.

The operation of my device is as follows: As the elevator-carriage 0 begins to descend, it, acting through the retarding-rope R and the moving pulley R at the top of the piston P, gives a motion (also descending, but with one-half the velocity of the carriage) to the piston D, and so long as the velocity is a safe one the valve D will remain down and off from its seat on the under side of the piston; but if the rate of speed exceed that of safety, or the rate at which it is desired that the carriage shall move, then the valve D closes onto the piston D and checks the speed.

The sliding valve D may be omitted and an automatic valve be placed in the pipe D if desired.

It will be observed that the pipe D is not an essential feature of my device.

I claim 7 In an elevator, the combination of the carriage C, retarding-rope R, piston D, having at the top of its rod P a pulley, R adapted to receive the retarding-rope R, and valve D with the cylinder D and retracting-weight P, substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 2d day of February, A. D. 1887.

WILLIAM E. NIGKERSON.

Witnesses:

FRANK G. PARKER, MATTHEW M. B'LUNT. 

